Object type system for a run-time environment using generated high-order language instructions for generic functions

Abstract

A static object system is provided to allow for code for implementing a run-time environment to be automatically generated that is compatible with a high-order systems programming language such as C. In particular, the meta-object system is static, object-oriented, and uses generic functions that can dispatch to an appropriate member function based on the types of one or more arguments. In one embodiment, the generated dispatch code uses a multi-way conditional branch.

Description

FIELD OF THE INVENTIONThe present invention relates to computer systems and more particularly to implementing a run-time environment.BACKGROUND OF THE INVENTIONA dynamic run-time environment for a language such as JAVA.TM. is responsible for managing memory for objects that are created and destroyed during the execution of a program. An object is an entity that encapsulates data and, in some languages, operations associated with the object. Since the encapsulated data is stored in memory, objects are associated with particular regions of memory that are allocated and deallocated by the dynamic run-time environment.In general, all implementations of a language run-time environment are built upon a low-level substrate that provides proto-language services. These services may include memory management, method dispatching, operating system (or other encapsulating environment) services, and outcall mechanisms. Typically, the low-level substrate and a schema of the system classes belongin...

AI Technical Summary

Benefits of technology

This and other needs are addressed by the present invention, in which a static, object-oriented meta-object system is provided for implementing a run-time environment. In particular, code is generated by the meta-object system that is compatible with a high-order systems programming language such as C. Since the meta-object system is object-oriented, the benefits of ease of design and maintenance associated with object-oriented programming are attained. Since meta-object system is static, each invoked method can be identified at compile-time, leading to efficient method dispatching. Finally, the meta-object system methods are translated into "generic functions" in a portable systems programming language such as C, thereby facilitating linkage with environmental code.

Problems solved by technology

Conventional techniques for implementing the low-level substrate services, however, suffer from several disadvantages, depending on the implementation language being used.

For example, if the low-level substrate is written in the C programming language and assembly language, the resulting code tends to be difficult to design and maintain in comparison with object-oriented programming languages.

Use of an objected-oriented language like the C++ programming language, however, also suffers from disadvantages.

In particular, C++ member functions (methods) are difficult to interface with generic C environmental code due to compiler name-mangling, and sometimes involve run-time overhead in method dispatching (i.e. invoking virtual member functions requires an indirection through a virtual table).

Furthermore, C++ is less portable than C.

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